I think this particular use case of PTFE makes it very prone to breaking up into small particles and ending up (quite permanently) in the environment and potentially in you. They're not very strong garments.

But this is true of most plastic fabrics, and plastic fabric is to blame for much of the microplastics in our lifestyles. Just throwing a nylon top into the dryer and you'll see all the lovely little plastic fabric particles making their way into your laundry.